High tension apparatus



Oct. 16, 1934. EHRLICH ET AL 1,977,122

HIGH TENS ION APPARATUS Filed March 50, 1951 50 swam Louis v W////am 6: Sc/mewer.

Patented Oct. 16, 1934 UNITED STATES HIGH TENSION APPARATUS Louis B. Ehrlich, Toledo,

and William G.

Schneider, Maumee, Ohio, assignors to The Electric Auto-Lite Company, Toledo, Ohio, a

corporation of Ohio Application March 30, 1931, Serial No. 526,292

3 Claims.

The invention relates to high tension apparatus, and particularly to coils suitable for use in the ignition system of internal combustion engines.

The invention has for an object to provide a coil structure wherein the elements of the coil per se are compactly assembled forming a very efficient and inexpensive structure.

The invention embraces the provision of a novel and efiicient method for securing lead wires to the coil windings and for insulating them from metallic contact with other parts.

Another object of the invention is to provide means for permanently insulating the high tension terminal from the metallic portions adjacent to the windings acting as a magnetic circuit.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of construction and to combination of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a vertical, longitudinal, sectional view through the coil of our invention;

Figure 2 is a detail sectional view taken substantially on a line 2-2 of Figure 1;

Figure 3 is an enlarged fragmentary detail view of a portion of the coil structure;

Figure 4 is a circuit diagram showing the coil of our invention incorporated in an ignition systom.

The invention may be contained in a high tension coil and for a practical application we have selected to illustrate the same as embodied in an ignition coil suitable for use in the ignition system of an internal combustion engine, but it is to be understood that we do not wish to limit our invention to the particular embodiment illustrated, and that we contemplate the use of our invention wherever the same may be found to be applicable.

4 Referring more particularly to Figure 1, the

coil structure comprises a core 5 which is preferably laminated and formed by assembling a plurality of iron or steel strips into a compact structure which is surrounded by a tube 6 of some suitable insulating material. Concentric with tube 6 is a tube 7 of insulating material on which the secondary or high tension winding 9 is wound.

Adjacent the secondary winding 9 is an insulating tube 11 upon which is wound a primary winding 12 superposed upon the secondary winding as shown in Figure 1. Surrounding the primary winding 12 is another insulating tube 14, the complete windings and core assembly being supported and housed within a cylindrical metallic casing 16. Between the insulating tube 14 and the walls of the casing 16 are interposed a plurality of metallic laminations 17 preferably of semi-circular formation and which are assembled as shown in detail in Figure 2. By these laminations an eflicient structure is produced, forming a path for the magnetic lines of force set up in the core and windings. The ends of these semi-cylindrically formed laminations 17 are slightly separated to decrease or reduce eddy currents.

One end of the core 5 is inserted into a bore in a supporting member 18 which snugly fits within tube 11 and serves for properly supporting the core in fixed relation to the windings forming a unitary assembly. The member 18 may be of any suitable insulating material, as, for example, porcelain which possesses high insulating qualities. The end of the casing 16 is adjacent to member 18 and is adapted to be enclosed by means of a circular cover 20.

The other end of casing 16 is enclosed by a member or cap 22. The member or cap 22 is preferably made of suitable molded insulating material, and is provided with a metallic flange 24 which serves to secure the cap to the casing in any suitable manner as by soldering illustrated at 23. The inner end of said cap is provided with a frustro-conical bore which receives and supports the other end of the magnetic core structure 5. The outer extremity of the member or cap 22 is provided with a central upstanding boss having a bore 26 which contains a metallic thimble 27 forming the high tension terminal for the secondary winding, the thimble being connected to one end of the winding by means of a lead 29. 95

To prevent any connection between the high tension terminal 29 and the core 5, in the embodiment disclosed, we completely enclose the core with suitable insulating material, such as the cup shaped member 39. As shown in Fig. 3 the 1 inside of the extended portions of the cup shaped member 39 fit snugly over the outside of the tube 6, while the enclosed part of the cup member 39 engages the end of the core, and completely insulates the same.

We have found that in order to prevent a derangement or loosening of the wire of the secondary winding it is desirable to pass the lead 29 through a small aperture in the outer insulating tube 7 surrounding the core 5 as particularly 110 shown in Figure 3 the lead being interposed between the adjacent walls of the tubes 6 and I.

- Toinsure proper position and obtain satisfactory insulation of the lead 29, we found it desirable to use a small tubular member 8 of suitable insulating material. One end of the tubular member 8 is interposed between the walls of tubes 6 and '7,

and the other end is interposed between the bore in member 22 and the cup shaped member 39, which positions the tubular member 8 enclosing the lead 29, whereby the lead 29 is completely insulated from the core 5 and permanently positioned with respect to the core.

Positioned adjacent to the upstanding boss of member or cap 22 are the primary terminals 30 and 31 connected to the respective ends of the primary windings by means of leads 32 and 33.

The terminals 30 and 31 are provided with ing knurled tenons 35 which are imbedded in the molded portion of member 22. By this arrangement, a high degree of insulation between terminals is insured. In the embodiment shown we prefer to enclose each lead wire 32 and 33 in insulating tubes 38 extending from the primary windings to the terminals 30 and 31. Tubes 38 serve for properly locating the leads with respect to the windings and prevent any mechanical or electrical stress from affecting the primary leads.

The other end of the high tension winding is preferably connected to one of the primary leads as 32, the same being also enclosed and properly insulated from the remaining parts of the coil structure as by means of a tubular member 38. Partially surrounding the shell 16, we provide a bracket 52 which serves for supporting the coil and positioning the same with respect to the mechanism or. apparatus with which the coil is afi'ording ignition. Struck up portions 53, suitably spaced from each other, cooperate with the bracket 52, and serve to retain the same in place.

These struck up portions act as reinforcing means against any stresses on the outside metallic shell 16. Bracket 52 may be secured to shell 16 by any suitable means as by welding. Suitable openings are provided in the extremities of bracket 52 for aflixing the coil in any desired position.

Referring to Figure 4, there is shown a circuit arrangement in which the structure described may be employed.

One terminal of the battery 40, as a storage battery, or other source of current, is connected to the frame of the motor vehicle or other apparatus with which used, such connection being indicated by ground at 41. The other terminal of the battery 40 is connected through switch 42 to either terminal of the primary 12, that is, to either of the tenons 35. In the example illustrated, the battery is shown as connected to the tenon 30, to which is also connected the outer terminal of the secondary 9. The other terminal of the primary 12 connecting with the terminal or binding post 31 connects with the movable contact 43 of the timer or interrupter, whose stationary contact is indi cated at 44, and as grounded at 45. The movable contact 43 is operated, as well understood in the art, by a cam 46 driven in definite relation with 46, and coming successively into high tension current transfer relation with the stationary distributor contacts 49, each connected with a spark plug 50.

The coil structure is assembled before placing the cap 22 in position and any remaining cavities are filled with an insulating compound 59 which is impervious to moisture and which serves as an additional means to prevent derangement of the parts in the casing.

We have distributed the dielectric stresses produced by high inductive effects and oscillating currents close to the magnetic core by spacing the turns or convolutions of the innermost and outermost layers of the secondary winding whereby a material saving is effected in the copper wire and insulating material used in the wind- We have found it desirable in order to produce a coil of high efficiency to decrease the number of turns in each successive layer in the primary winding, though it may be wound with an equal number of turns which does not materially interfere with the successful operation of the coil.

It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, tltie invention comprehending all variations there- 0 What we claim is:

1. In a high tension coil, the combination of a core of magnetic material, a high tension secondary winding adjacent said core, a low tension primary winding adjacent said secondary winding, a high tension terminal, low tension terminals, and means including an insulating cup having side walls surrounding the core and a bottom wall contacting with said core for insulating said high tension terminal from said core.

2. In a high tension coil, a laminated core; insulating material surrounding said core; a high tension winding supported by said insulating material; a low tension exciting winding surround- 1 ing said high tension winding; a metallic casing enclosing said windings; a plurality of members in said casing for fixedly locating said core; a terminal supported by one of said members in axial alignment with said core; a connecting means between said high tension winding and said terminal; means for insulating said connecting means from said core including a tubular member surrounding said connecting means, and a cup shaped member having a wall contacting with the end of said core adjacent said terminal.

3. In an ignition coil, a magnetic core; high and low tension windings surrounding said core; a metallic casing surrounding said windings and core; an end cover for said metallic casing of insulating material having a tubular portion sur- 

